Disposable absorbent pants with advantageous stretch and manufacturability features, and methods for manufacturing the same

ABSTRACT

A disposable absorbent pant that includes a central chassis and a belt structure is disclosed herein.

BACKGROUND

Currently, disposable absorbent pants are manufactured and marketed forwear by toddlers and young children who are not yet toilet trained,older children who are experiencing childhood enuresis, and adultssuffering from incontinence. A disposable absorbent pant usuallyincludes a central chassis having a core formed of absorbent material,enveloped between a liquid permeable, wearer-facing topsheet, and aliquid impermeable, outer- or garment-facing backsheet. The chassis isusually adapted to be positioned on the wearer such that it wrapsbetween the wearer's legs and upwardly about the lower torso, such thatthe front and rear ends extend toward the wearer's waistline in thefront and rear, respectively. The chassis is often joined to a pair ofside/hip panels that connect front and rear regions of the chassis oneither side thereof, thereby forming a pant structure. In many currentdesigns, the side/hip panels are manufactured so as to be elasticallyextensible in the lateral direction, providing stretchability that easesdonning, while providing a relatively snug and comfortable fit oncedonned. Disposable absorbent pants are usually manufactured in one oftwo differing overall configurations.

In the first configuration, the backsheet and topsheet of the centralchassis structure extend to, and form, the front and rear waist edges ofthe pant in the regions near the wearer's navel in the front, and smallof the back in the rear. Separate and discrete side/hip panels arejoined to longitudinal (side) edges of the central chassis structure inits front and rear regions, joining them to form the pant structure. Anexample of this type of configuration is currently manufactured and soldin the United States by The Procter & Gamble Company under the trademarkPAMPERS EASY UPS.

In the second configuration, the central chassis structure does notextend to, or form, the front and rear waist edges of the pant. Rather,an elasticized belt structure entirely encircles the wearer's waist andforms the waist edge about the entire pant, and the side/hip panels. Thecentral chassis is joined to the belt structure, usually on the insidethereof, with its ends disposed at locations in the front and rear waistregions somewhat below the waist edges of the belt structure. Thissecond configuration is sometimes known as a “belt” or “balloon”configuration (hereinafter, “belt” configuration). An example of thistype of configuration is currently manufactured and sold in Asia by TheProcter & Gamble Company under the trademark PAMPERS, and also byUnicharm Corporation under the trademark MAMY POKO.

While both configurations have their advantages, in some circumstances abelt configuration may be deemed desirable. Among other advantages,because the encircling belt may be made elastically extensible in thelateral direction, considerable elastic stretch and contraction as wellas targeted elastic profiles may be provided entirely about the wearer'swaist.

For purposes of optimal fit, appearance and containment, it may bedesired that a pant have elastic extensibility not only laterallyhoop-wise about the waist and hips, but also hoop-wise about each of thelegs, so as to provide an elasticized leg band or leg band-likestructure. This may be accomplished by incorporating elastic membersinto the structure that at least partially encircle the leg openings, inaddition to the laterally extending elastic members encircling the waistopening. Although some currently manufactured belt configuration pantsinclude such an arrangement of elastic members, they could be deemed tohave a rough or unfinished appearance, or are inefficient tomanufacture, or both. For example, some current designs have elasticmembers that continue across front and rear regions of the chassis,having no important function and creating an unsightly appearance.

Therefore, improvements to the design of disposable absorbent pants of abelt configuration, that provide for elasticized leg band-like featuresthat and also efficient manufacturability, would be advantageous.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is simplified perspective view of a disposable absorbent pant;

FIG. 2 is a simplified plan view of a precursor structure of adisposable absorbent pant, shown with inner or wearer-facing surfacesupward;

FIG. 3A is a simplified, schematic cross-section view taken through line3-3 of FIG. 2, in one example of a possible configuration;

FIG. 3B is a simplified, schematic cross-section view taken through line3-3 of FIG. 2, in another example of a possible configuration;

FIG. 3C is a simplified, schematic cross-section view taken through line3-3 of FIG. 2, in another example of a possible configuration;

FIGS. 4A-4K are simplified, schematic cross-section views taken throughline 4-4 of FIG. 2, in various examples of possible configurations;

FIG. 5A is a plan view of a portion of a nonwoven web with appliedelastic members;

FIG. 5B is a simplified schematic view of equipment and components formanufacturing a laminate, shown along a cross-direction view;

FIG. 6A is a plan view of a portion of a multilayer web shown with cutlines;

FIG. 6B is a plan view of a portion of a multilayer web shown with cutlines in an alternative configuration;

FIG. 6C is a plan view of portions of the multilayer web as shown inFIG. 6A, with a middle section severed away;

FIG. 6D is a plan view of portions of the multilayer web as shown inFIG. 6B, with a middle section severed away;

FIG. 6E is a simplified schematic view of equipment and components formanufacturing a laminate, shown along a cross-direction view;

FIG. 7 is a plan view of a multilayer web and applied chassis structuresillustrating a method for manufacturing pant structures;

FIG. 8 is a plan view of a portion of a multilayer web including twononwoven layers and a pre-strained elastic member, with formations ofshirrs along the elastic member in the nonwoven layers;

FIG. 9 is a cross-section view along line 9-9 in FIG. 8; and

FIGS. 10A-10C are cross-sections similar to that of FIG. 9, butincluding a third layer and showing examples in which a third layer maybe included and attached in an elasticized multilayer web structure andimparted with differing patterns of shirrs.

DESCRIPTION OF EXAMPLES Definitions

“Cross direction” (CD)—with respect to the making of a nonwoven webmaterial, the nonwoven material itself, a laminate thereof, or anarticle in which the material is a component, refers to the directionalong the material substantially perpendicular to the direction offorward travel of the material through the manufacturing line in whichthe material and/or article is manufactured.

As used herein, the term “elastic” or “elastomeric” refers to theproperty of an extensible material (or a composite of multiplematerials) that can extend, without substantial rupture or breakage, toa strain of 100% in the Hysteresis Test, with a set less than or equalto 10% of the elongation as measured according to the Hysteresis Test.An elastic material is considered elastically extensible.

“Machine direction” (MD)—with respect to the making of a nonwoven webmaterial, the nonwoven material itself, a laminate thereof, or anarticle in which the material is a component, refers to the directionalong the material substantially parallel to the direction of forwardtravel of the material through the manufacturing line in which thematerial and/or article is manufactured.

“Lateral”—with respect to a pant and its wearer, refers to the directiongenerally perpendicular with the wearer's standing height, or thehorizontal direction when the wearer is standing. “Lateral” is also thedirection generally perpendicular to a line extending from the midpointof the front waist edge to the midpoint of the rear waist edge.

“Longitudinal”—with respect to a pant and its wearer, refers to thedirection generally parallel with the wearer's standing height, or thevertical direction when the wearer is standing. “Longitudinal” is alsothe direction generally parallel to a line extending from the midpointof the front waist edge to the midpoint of the rear waist edge.

FIG. 1 is a general simplified perspective depiction of a disposableabsorbent pant 10 having a belt configuration. Pant 10 may include acentral chassis 20 and a belt structure 30. Belt structure 30 may beelastically extensible in the lateral direction, providing elasticstretchability for ease of donning, and a snug and comfortable fitfollowing donning. Central chassis 20 may include a wearer-facing,liquid permeable topsheet (not specifically shown in FIG. 1), an outer-or garment-facing backsheet (not specifically shown in FIG. 1) and anabsorbent core (not specifically shown in FIG. 1) sandwiched orenveloped between the topsheet and backsheet. A pair of laterallyopposing, longitudinally extending barrier cuffs 25 also may be includedwith the central chassis in a crotch region thereof, disposed adjacentto the topsheet. Generally the central chassis and barrier cuffs mayhave any construction and components, including leg cuff structures,suitable for disposable diapers, training pants, and adult incontinencepants, such as, but not limited to, those described in U.S. provisionalpatent application No. 61/480,663 and application(s) claiming prioritythereto. Belt structure 30 may have a front portion 31 and a rearportion 32. Front and rear portions 31, 32 may be joined together atrespective left and right side seams 33 l, 33 r. Belt structure 30 mayform front and rear waist edges 11, 12 defining waist opening 15, and atleast portions of left and right leg opening edges 13 l, 13 r of thepant 10.

FIG. 2 is a simplified plan view of the precursor structure of the pant10 shown in FIG. 1, shown prior to joining of front and rear portions31, 32 along their respective side edges 34 l, 35 l and 34 r, 35 r.Front region 31 a, including front portion 31, and rear region 32 a,including rear portion 32, may each include anywhere from 25 percent to40 percent of the overall longitudinal length of the precursorstructure; correspondingly, a crotch region 45 may include anywhere from20 percent to 50 percent of the overall longitudinal length of theprecursor structure, with at least a portion thereof lying at lateralaxis LA. To form pant 10, the precursor structure may be folded alonglateral axis LA to bring front and rear regions 31 a, 32 a, and frontand rear portions 31, 32 together such that their side edges 34 l, 35 land 34 r, 35 r, respectively, may be joined at seams 33 l, 33 r (asshown in FIG. 1). Seams 33 l, 33R may be formed by adhesive, thermal,pressure, or ultrasonic bonding, and combinations thereof. In analternative example, the seams may be formed by mechanical fastenerssuch as cooperating pairs of hook-and-loop fastening components disposedalong side edges 34 r, 35 r and 34 l, 35 l. Fasteners may also includetape tabs, interlocking fasteners such as tabs & slots, buckles,buttons, snaps, and/or hermaphroditic fastening components. Exemplarysurface fastening systems are disclosed in U.S. Pat. Nos. 3,848,594;4,662,875; 4,846,815; 4,894,060; 4,946,527; 5,151,092; and 5,221,274,while an exemplary interlocking fastening system is disclosed in U.S.Pat. No. 6,432,098. The fastening system may also include primary andsecondary fastening systems, as disclosed in U.S. Pat. No. 4,699,622.Additionally exemplary fasteners and fastener arrangements, thefastening components forming these fasteners, and the materials that aresuitable for forming fasteners are described in U.S. PublishedApplication Nos. 2003/0060794 and 2005/0222546 and U.S. Pat. No.6,428,526.

Still referring to FIG. 2, one or both of front and rear portions 31, 32may include at least a first elastic member 36, 37 disposed nearer thewaist edges 11, 12 and at least a second elastic member 38, 39, disposednearer the leg opening edges 13 l, 13 r. As suggested in FIG. 2, one ora plurality of waist elastic members 36, 37 may be disposed in asubstantially straight lateral orientation, and one or a plurality ofleg elastic members 38, 39 may be disposed along curvilinear paths toprovide hoopwise elastic stretch about the leg openings 13 l, 13 r (asshown FIG. 1). For purposes of manufacturing a pant having a neatappearance as will be described below, it may be desired that legelastic members 38, 39 terminate proximate the respective longitudinaledges 21 of chassis 20. For purposes herein, where used to describe apositional relationship between two features, “proximate” is intended tomean within 2.0 cm, more preferably within 1.0 cm, of the identifiedfeatures.

Elastic members 36, 37, 38 and 39 may be in the form of film or sectionsor strips thereof, strips, ribbons, bands or strands of circular or anyother cross-section, formed in any configuration of any elastomericmaterial such as described in, for example, co-pending U.S. applicationSer. Nos. 11/478,386 and 13/331,695, and U.S. Pat. No. 6,626,879. Asuitable example is LYCRA HYFIT strands, a product of Invista, Wichita,Kans.

FIGS. 3A-3C are examples of potential longitudinal cross-sections takenat line 3-3 through the rear portion 32 of the belt structure and rearregion of the pant as shown in FIG. 2, depicting features in threepossible configurations. It can be appreciated that in each of theseparticular examples, the cross-section may substantially mirror across-section taken through the front portion 31 of the belt structureand the front region of the pant.

FIG. 4A is an example of a potential longitudinal cross-section taken atline 4-4 through the rear portion 32 of the belt structure and rearregion of the pant as shown in FIG. 2, depicting features in oneconfiguration. It can be appreciated that this cross-section may also bea substantial mirror image of a cross-section taken through the frontportion 31 of the belt structure and the front region of the pant. Beltstructure 30 where shown in FIG. 4A has the same layers and componentsas those depicted in FIG. 3A, hut with the addition of leg elasticmembers 39 and without the chassis components, as a result of thelocation of the cross-section. As suggested in FIG. 2, leg elasticmembers 39 may terminate proximate the longitudinal edges 21 of centralchassis 20; thus, they do not appear in FIGS. 3A and 3B. Additionalelastics (not shown) may be disposed longitudinally between the waistelastics and the leg elastics shown in FIGS. 4A-4K.

Referring to FIGS. 3A-3C, chassis 20 may have liquid permeable topsheet22 forming at least a portion of its inner, wearer-facing surface.Topsheet 22 may be formed of a nonwoven web material which is preferablysoft and compatible with sensitive skin, and may be formed of and haveany of the features of topsheets used in disposable diapers, trainingpants and inserts including those described in, for example, co-pendingU.S. application Ser. No. 12/841,553. Chassis 20 may also have anoutward-facing backsheet 24, which may be liquid impermeable. Backsheet24 may be formed of and have any of the features of backsheets used indisposable diapers and training pants including those described in, forexample, the co-pending U.S. patent application referenced immediatelyabove. Chassis 20 may also have an absorbent core 23 disposed betweentopsheet 22 and backsheet 24. Absorbent core 23 may include one or moreabsorbent acquisition, distribution and storage material layers and/orcomponents; it may be formed of and have any of the features ofabsorbent cores used in disposable diapers and training pants includingthose described in, for example, the co-pending U.S. patent applicationreferenced immediately above.

As suggested in FIGS. 3A-3C, chassis 20 may be affixed to a beltstructure 30, to the inner, wearer-facing side thereof, oralternatively, to the outer, garment-facing surface thereof. Chassis 20may be bonded to the belt structure 30 by adhesive, by thermalbonds/welds, mechanical fasteners or a combination thereof.

Referring to FIGS. 3A and 4A, belt structure 30 may have a first beltlayer 40, which may be formed of a suitable nonwoven web material. Sincethe first belt layer may come into direct contact with the wearer'sskin, it may be deemed preferable to select a nonwoven web material forthe layer that is soft, comfortable and relatively breathable/vaporpermeable. One or more waist elastic members 37 may be disposed betweenfirst belt layer 40 and a second belt layer 41. Second belt layer 41 maybe formed of the same, similar or differing nonwoven web material asfirst belt layer 40. First belt layer 40 and second belt layer 41 may bebonded together by adhesive, a pattern of thermal bonds or a combinationthereof such that first belt layer 40 and second belt layer 41 form alaminate, with the one or more waist elastic members 37 sandwiched andaffixed there between. Similarly, referring to FIG. 4A, the one or moreleg elastic members 39 may be affixed and sandwiched between first beltlayer 40 and second belt layer 41.

Referring to FIGS. 8 and 9, during manufacture, the one or more waistelastic members 37 may be pre-strained along the direction of theirlengths or longer dimensions, before they are affixed between the beltlayers, such that, upon completion of manufacture and subsequentrelaxation, contraction of elastic members 37 will induce a pattern ofwrinkles, pleats, corrugations or rugosities (hereinafter, “shirrs”) 43in first belt layer 40 and second belt layer 41. The shirrs 43 areformed of material that gathers about the elastic members as theycontract, and the gathered material serves to accommodate stretching andcontraction of the belt structure 30. The shirrs 43 are oriented alongfold or bending lines roughly transverse or perpendicular to thedirection of lateral contraction of the elastic members 37.

Similarly, the one or more leg elastic members 39 may be pre-strainedalong their paths of placement (which, as noted, may be curvilinear)during manufacture before they are affixed between the layers, suchthat, upon completion of manufacture and subsequent relaxation,contraction of elastic members 39 will induce a pattern of shirrs infirst belt layer 40 and second belt layer 41. These shirrs are alsoformed of material that gathers about the elastic members as theycontract, and serve to accommodate stretching and contraction of thebelt structure 30 about the leg openings. The shirrs are oriented alongfold or wrinkle lines roughly transverse or perpendicular to thedirection of contraction of the elastic members 39.

Still referring to FIGS. 8 and 9, patterns of deposits of adhesive maybe applied to either of the layers 40, 41, and/or to the elastic members37, 39 to adhere the layers to the elastic members 37, 39 at adheredportions 44, in regular patterns and/or intervals, so that the shirrsformed upon relaxation and contraction of elastic members 37, 39 aresomewhat uniform, evenly distributed and neat in appearance.

Also as shown in FIGS. 3A-3C and 4A-4K, the belt structure may include alongitudinally extending wrapping layer 42. Wrapping layer 42 may form alayer that wraps not only about the front and rear portions of the beltstructure, but also extends from the front portion, around and beneaththe chassis 20 through the crotch region, and into the rear portion. Thewrapping layer 42 may be formed of a single material web disposed as alayer of the rear portion 32 of the belt structure 30, the centralchassis 20, and the front portion 31 of the belt structure 30. Wrappinglayer 42 may be disposed so as to form an outer layer of the beltstructure 30 in the front and rear portions as suggested in FIGS. 3A and4A-4G, an intermediate layer in the front and rear portions as suggestedin FIGS. 3B and 4H, or an inner layer as suggested in FIGS. 3C and 4K.Wrapping layer 42 may be formed of any suitable nonwoven web materialhaving desired properties of softness and mechanical strength.

Wrapping layer 42 may be added to the belt structure 30 in a stepoccurring later than the step in which the first belt layer 40, elasticmembers 36, 37, 38 and 39, and second belt layer 41 are joined. In somecircumstances the shirrs in layers 40, 41 caused by attachment of theelastic members to layers 40 and 41 and relaxation and contraction ofelastic members 36, 37, 38 and 39 from a pre-strained state may beformed in a manner to provide a relatively smooth texture and surfaceagainst the skin of the wearer. Referring to FIGS. 10A-10C, oneadvantage provided by a third layer is that, during a step followinglamination of the portions of belt structure 30 including layers 40 and41, with one or more elastic members 36, 37, 38 and 39 there between,the wrapping layer 42 may be joined to the outside surface of secondbelt layer 41 at attachment points 46 to form a distinct and differentconfiguration of second shirrs 47. As a result, wrapping layer 42 may beimparted with larger second shirrs than exist on first or second beltlayers 40, 41, providing an appearance of a greater degree of stretchand/or lofty feel. Differences in appearance and/or height and spacingof shins in the belt laminate formed by, e.g., layers 40, 41 andinterposed elastic elements can be achieved by differing the types ofadhesive and/or differing patterns of adhesive deposits or mechanicalbonds, used to affix wrapping layer 42 to the other layers at attachmentpoints 46. For example, the elastic members may be joined to the firstbelt layer 40 and second belt layer 41 by a first adhesive or mechanicalbond pattern that produces a first configuration of shirrs, and thisprecursor elasticized multilayer web structure may then be joined to thewrapping layer 42 via a different pattern of adhesive deposits,resulting in a distinctly different configuration of shins from that ofthe precursor elasticized multilayer web structure. Such a differencemay provide for enhanced visual and tactile softness attributes, fewerinstances of skin irritation or marking that can result fromconcentrations of pressure at shirrs, less bulk under clothing, improvedstretch and other perceptual advantages. In an alternative example, oneor more of the layers 40, 41 and/or 42 may include an extensible poroussubstrate such as an elastomeric nonwoven material (i.e., a nonwovenmaterial whose fiber constituents are formed of elastomeric polymer(s))or an elastomeric foam material, which may be applied in a partiallystrained state, thereby reducing the size of the shirrs in such layerwhen the belt is in its relaxed, contracted state. Additionally, as maybe appreciated from FIG. 3A, in one configuration wrapping layer 42 maybe disposed to cover over the junction between central chassis 20 andthe belt structure 30, concealing it and further contributing to asmooth, unified outward appearance. It will be appreciated that FIGS.10A-10C are non limiting examples, and other configurations of threelayers of web material with elastic members disposed there between maybe manufactured to impart differing patterns of shins in the respectivelayers.

Examples of suitable nonwoven web materials useful for forming any oflayers 40, 41 and 42 are described in co-pending U.S. application Ser.No. 13/090,761.

FIGS. 4B-4K depict alternative configurations that cross-section 4-4(FIG. 2) may have, according to differing embodiments of a pant with abelt structure having a first belt layer 40, second belt layer 41, andwrapping layer 42. As may be appreciated by a comparison of FIGS. 4A and4B-4C, and 4D-4E, waist elastic members 36, 37 and leg elastic members38, 39, may be disposed between differing pairs of layers 40, 41 and 41,42, and may have alternating dispositions between layers. These varyinglocations of disposition of elastic members provide for flexibility inmanufacturing and/or alteration of the outward appearance of the pant.For example, it may be desired that shirrs imparted by relaxation andcontraction of pre-strained elastic members be accentuated at the waistline and/or at the leg band area, which may signal fit andstretchability to the consumer. In this circumstance, it may be desiredto dispose, e.g., waist elastic members 36, 37 between an intermediatelydisposed belt layer and an outwardly-disposed layer. Alternatively, itmay be desired that the appearance of shirrs be partially subdued orconcealed. In this circumstance, it may be desired to dispose, e.g., legelastic members 38, 39 between an intermediately-disposed layer and aninwardly-disposed layer. In another alternative, disposing the elasticmembers between an outwardly-disposed layer and anintermediately-disposed layer may impart a smoother texture to theinwardly-disposed layer, thereby providing a more comfortable surfacenext to the wearer's skin. In the alternatives depicted in FIGS. 4D and4E, alternating disposition of elastic members between differing layerpairs may serve to allow a closer longitudinal distribution of elasticmembers for a greater force profile in one or both of the waist band andleg band areas, than would be achievable if all elastic members aredisposed between the same layers, because, during manufacture, it may bedifficult to achieve close longitudinal spacing when applying elasticmembers to a web, without having the members bunch together in somelocations—particularly when they are applied along a curvilinear path.

In still other examples, elastic members along the waist or leg bandareas may be added about the waist opening or leg openings outside theoutermost layer. Referring to FIGS. 4F and 4G, added elastic members 37a, 39 a may be substituted for elastic members 37, 39, or my besupplemental to them. Added leg elastic members 39 a and waist elasticmembers 37 a may be first incorporated into elasticized band structureshaving inner and outer band layers 51, 52 as suggested in FIGS. 4F and4G. The inner and outer band layers 51, 52 may be formed of respectivenonwoven web materials, film materials or a combination thereof. In oneexample, a single layer may be folded over on itself to enclose andsandwich added elastic members 37 a and/or 39 a there between. In oneembodiment the leg elastic members may be applied between two carrierlayers in a linear fashion to create an elastic leg band laminate, andthe elastic leg band laminate may subsequently be applied to theoutermost layer or to a portion of the belt structure along acurvilinear path. Placing elastic laminates of outer band layers 51 and52 with elastic members there between at the outer surfaces of the pantmay provide a visual signal of stretchability and fit and a neat bandedappearance, while moving the elastic members and resulting shirrs to theouter portions of the structure and away from the wearer's skin.

One or more of elastic members 36, 37, 38 and 39 may be varied from oneor more of the others in various ways to impart differing stretch andforce characteristics. For example, it may be desired that curvilinearleg elastic members exert greater or less tension about the leg openingsthan exists about the waist opening during wear, for fit snugness aboutthese openings that differ according to specific design circumstances.One or more of the elastic members 36, 37, 38 and 39 may be selectedand/or configured so as to differ from one or more of the others in arespect selected from number of elastic strands or bands,cross-sectional size of elastic strands or bands, cross-sectional shapeof elastic strands or bands, chemical composition of material from whichelastic strands or bands are formed, amount of pre-strain imparted tothe elastic strands or bands during manufacture of the pant, spacing ofthe strands and combinations thereof.

In addition to the waist elastic members 36, 37 and curvilinear legelastic members 38, 39, additional elastic members (not shown) may beincluded longitudinally there between, to impart additional stretch,contraction and load/force bearing capability to the belt structure, inthe same manner as such capability is imparted by the waist and legelastic members. The additional elastic members may be disposed betweenthe same pairs of layers as any of elastic members 36, 37, 38 and 39, ormay be disposed between differing pairs of layers, and may be disposedin alternating locations between differing pairs of layers as describedabove.

Some examples described above, as well as other examples not expresslydescribed, may also be advantageous because they may lend themselves torelatively efficient manufacture.

Referring to FIGS. 5A and 5B, a first nonwoven web 70, to be used toform one of first belt layer 40 or second belt layer 41 for both frontportion 31 and rear portion 32 (see FIG. 2), may be conveyed in amachine direction MD. As first nonwoven web 70 travels in the machinedirection, one or more leg elastic members 38, 39 may be applied to thefirst nonwoven web 70 along one or more curvilinear paths.(Alternatively, some of the elastic members may be applied at a laterstep, as described below.) The respective curvilinear paths for elasticmembers 38, 39 may mirror each other about a machine direction axisalong the web, or they may differ in some respects, to provide leg bandprofiles that vary from front to rear of the finished product. Referringto FIG. 7, the curvilinear paths for the elastic members 38, 39 may bearranged such that, when they are severed as described below, thesevered ends are proximate to, and even meet, or align with, complement,and/or effectively form extensions of, leg cuff elastic members 21 apresent on leg cuff components of central chassis 20. This provides forthe appearance and/or function of an elasticized leg band thatcompletely encircles the wearer's leg. The leg elastic members may beapplied along the curvilinear paths via methods and equipment describedin, for example, U.S. Pat. Nos. 8,062,454 and 8,075,722 or U.S.application Ser. Nos. 12/362,981; 12/363,002; 12/363,023; and12/363,048.

Simultaneously with, or before or after this step, one or more waistelastic members 36, 37 may be applied to the first nonwoven web 70 alongsubstantially straight paths, and may be applied along the outer edges70 a, 70 b of the web and may be spaced at equal or varying intervalsthere from, but so as to be disposed approximately along a lateraldirection in the finished pant. In another example, the leg elasticmembers 38, 39, or fewer than all of them, may be applied to a secondnonwoven web layer 80 and/or an outer surface of a first elasticizedmultilayer web 90, following lamination in rollers 100, 101 as depictedin FIG. 5B.

As they are applied to a web, the elastic members may be pre-strained bya controlled amount in the direction of their greater lengths, such thatupon completion of manufacture and subsequent relaxation, shirrs ofgathered nonwoven material are created that will accommodate elasticstretch when the pant is donned and worn. The elastic members may beadhered to web 70 along their paths of application by an adhesiveapplied to the web or to the elastic members or both, prior toapplication. Referring to FIG. 5B, following application of the waistelastic members and leg elastic members to web 70, first nonwoven web 70and a second nonwoven web 80 (to form another of the component layers ofa belt structure) may be passed through the nip between a first pair oflaminating rollers 100, 101. If adhesive is applied to the surface atleast one of the webs 70, 80 facing the other, passage through thelaminating rollers will adhere the webs together and affix the elasticmembers in place between webs 70, 80 along their paths of application,and form a first elasticized multilayer web 90. In one example, thenonwoven web 80 may be a single continuous web extending across thecross direction to cover the entirety of web 70, or web 80 may be 2separate webs spaced apart in the cross direction, to cover only thefront and rear portions (i.e., relative FIG. 5A, the left and rightportions) of web 70. Alternatively or in addition, one or both ofrollers 100, 101 may have thereon a pattern of discrete bondingprotrusions and one or both of rollers 100, 101 may have heating energysupplied thereto, such that a corresponding pattern of discrete bondsthat affix webs 70, 80 together is impressed at the nip through heat,pressure or a combination thereof. It may be preferred, however, to useadhesive to form the laminate rather than heat/pressure bonding, sincethe latter method may damage the elastic members, and the former may bedeemed more reliable to affix and hold the elastic members in place andprevent displacement of the elastic members relative to web 90,resulting from their tendency to contract following pre-strain. Inanother alternative, however, adhesive may be used to adhere the elasticmembers along their paths of application, and heat/pressure bonds may beused to affix the webs 70, 80 together in areas not occupied by theapplied elastic members, the pattern of discrete bonding protrusions onone or both of rollers 100, 101 being arranged accordingly. In anotheralternative, the web 90 may be subjected to mechanical bonding followingformation of the laminate.

The above-described steps provide for the securement and bonding ofpre-strained elastic members, e.g., elastic members 38, 39, between twolayers of nonwoven web, in a manner that reduces the likelihood thatthat they will substantially snap back and curl at their severed ends,when portions of the web including the elastic members 38, 39 aresevered away as described below and illustrated in FIGS. 6A-6D. Thisprovides for a neater appearance in the finished product about, e.g.,leg openings, when such elastic members are severed proximate the legopenings.

Following its formation, in one alternative, first elasticizedmultilayer web 90 may be passed through incremental stretching and/orring-rolling equipment to impart, promote formation of, or affect theappearance of an orderly pattern of shirrs in the layers, as describedin, for example, U.S. Pat. Nos. 5,167,897; 5,156,793; and 5,143,679; orU.S. application Ser. Nos. 10/288,095; 10/288,126; 10/429,433;11/410,170; 11/811,130; 11/899,656; 11/899,810; 11/899/811; 11/899,812;12/204,844; 12/204,849; 12/204,854; 12/204,858; or 12/204,864 and theco-pending U.S. applications filed on the same day hereof in the namesof Zink et al., U.S. App. Ser. Nos. 13/893,405, 13/893,634, and13/893,735.

Referring to FIGS. 6A-6E, first elasticized multilayer web 90 may thenbe passed through cutting equipment that severs away middle section 97from web 90 along cut paths 96, and middle section 97 may then beremoved. This severs leg elastic members 38, 39 at repeated intervals assuggested in FIGS. 6A-6D, and leaves behind front and rear waistsections 98, 99 of first elasticized multilayer web 90. It may beappreciated from FIGS. 6B and 6D that cut paths 96 may also benonlinear, and that a cutting die may be configured to cut along acutting path that shifts in the cross direction, and/or is approximatelyparallel the path(s) of leg elastic members 38, 39. Also as suggested inFIGS. 6B and 6D, the cutting die may be configured to sever the legelastic members and the associated web layer(s) in the cross directionso as to effect a longitudinally-oriented cut and arrangement of thesevered ends of the leg elastic members in the finished pant, assuggested in FIGS. 1 and 2. Thus, in one example, it may be desired tocut elastic members 38, 39 along cross direction lines as suggested bycut paths 96 in FIG. 6B, rather than along machine direction lines assuggested by cut paths 96 in FIG. 6A. This enables the severed ends ofelastic members 38, 39 to be neatly arranged longitudinally, i.e., atsimilar lateral locations, along the longitudinal edges 21 of thecentral chassis 20 (e.g., see FIGS. 1 and 2).

Following the severing of the leg elastic members, in one alternative,one or more waist elastic members may be applied to the front and rearwaist sections 98, 99, in the event it is desired to supplement waistelastic members already added and disposed between the same pair oflayers as the leg elastic members, or, in another alternative, in theevent it is desired that waist elastic members be disposed between adiffering pair of layers than leg elastic members 38, 39.

Referring to FIG. 6E, front and rear waist sections 98, 99 together witha third layer web 91 (which also may be a nonwoven web) may then bepassed through the nip between a second pair of laminating rollers 102,103 to form a second elasticized multilayer web 95 that is a precursorto a belt structure. Prior to passing front and rear waist sections 98,99, and web 91 through the nip between rollers 102, 103, one or both ofthe front and rear waist sections 98, 99 may be shifted in the crossdirection to increase or decrease the spacing between the front and rearbelt sections. Additionally, one or both of the front and rear waistsections may be allowed to partially (but not entirely) relax andcontract along the machine direction through contraction of thepre-strained elastic members. This will allow third layer web 91 to beapplied to the laminate in a manner that results in shins in web 91about the elastic members that are fewer in number, and/or lower inheight/depth, and/or spaced differently, compared with those resultingin the first and second nonwoven webs in the finished product, andthereby, provide a differing appearance and/or feel to the outer layerweb component of the belt structure. Third layer web 91 may be affixedto front and rear waist sections 98, 99 by adhesive applied to one ormore of the acing surfaces thereof in a continuous web-like application,or a continuous or discontinuous pattern; as noted above, the patternmay be configured to affect the features of shins that appear in thethird layer. Alternatively or in addition, one or both of rollers 102,103 may have thereon a pattern of discrete bonding protrusions and oneor both of rollers 102, 103 may have heating energy supplied thereto,such that a corresponding pattern of discrete bonds that affix webs 90,91 together is impressed at the nip through heat, pressure or acombination thereof. The pattern may be arranged so as to avoid theareas occupied by the elastic members so as not to damage them, and toprovide an appearance that does not have a distinct pattern of shirrs.

There are several advantages provided by including a third layer (inaddition to elastic members) in the belt structure as described herein.First, as described above, including three layers allows for formationof a differing pattern of shirrs, exposed on either the inside oroutside of the belt structure, than the pattern formed in the first twolayers. Second, inclusion of a third layer provides options concerningthe locations of elastic members in differing areas (e.g., waistbandarea and legband area) between differing pairs of layers. See, e.g.,FIGS. 4A-4C, 4D, 4E, and 4H-4J. This allows the manufacturer tomanipulate the mechanical properties, comfort and appearance of the beltstructure.

Following its formation, in one alternative, second elasticizedmultilayer web 95 may be passed through incremental stretching and/orring-rolling equipment to impart or promote formation of an orderlypattern of shirrs in the layers, as described in, for example, U.S. Pat.Nos. 5,167,897; 5,156,793; and 5,143,679; or U.S. application. Ser. Nos.10/288,095; 10/288,126; 10/429,433; 11/410,170; 11/811,130; 11/899,656;11/899,810; 11/899/811; 11/899,812; 12/204,844; 12/204,849; 12/204,854;12/204,858; or 12/204,864 and the co-pending U.S. applications filed onthe same day hereof in the names of Zink et al., U.S. App. Ser. Nos.13/893,405, 13/893,634, and 13/893,735.

Following that step, referring to FIG. 7, central chassis 20 structuresmay be applied to either surface of second elasticized multilayer web 95and affixed thereto by any suitable method including thermal bonding,adhesive bonding, mechanical fastening or a combination thereof. Wherecentral chassis 20 includes elasticized leg cuff structures, forexample, such as described in U.S. provisional patent application No.61/480,663, with leg cuff elastic members 21 a, these may be directlyaffixed to the belt structure at cuff bonding locations 21 b proximatethe severed ends of leg elastic members 38, 39; this may provide foreffective creation of an elasticized cuff/banding structure thatsubstantially or entirely encircles the wearer's leg.

Lastly, individual pant precursor structures such as shown in FIG. 2 maybe severed and separated from the web along separation lines 120.Simultaneously with or prior this severing step, leg opening cutouts 111may be made in the outer layer web 91 component of web 95. A singlerolling cutting die may be made and paired with an anvil roller to forma cutting nip that effects cutting along separation lines 98 and legcutouts 111 in a single operation. (As noted above, in anotheralternative, leg opening cutouts may be made simultaneously with thecutting step described above in which middle section 97 is cut away,along cut lines 96, as suggested in FIGS. 6B and 6D.) The final cuttingstep severing the web along separation lines 120 sever away individualpant precursor structures, such as shown in FIG. 2, for example.

In another alternative, however, the entire second elasticized web 95combined with applied central chassis 20 structures, may be passedthrough a folding device (not shown) prior to severing away individualpant structures. The folding device may be configured to fold the entirecombined web 95 and chassis 20 structure along a fold line 110 extendingin the machine direction, central chassis 20 to the inside of the fold,thereby bringing front portions 31 and rear portions 32 together priorto severing away pant structures. Thereafter, the combined, folded web95 and central chassis 20 may be passed through seaming and cuttingequipment that forms seams along both sides of separation lines 120,joining front portions 31 and rear portions 32 at side seams 33 r, 33 l(see FIG. 1), and severs away individual pants 10 from the web 95. Itmay be desirable that this final seaming and cutting operation beperformed simultaneously, wherein the seaming and cutting equipmentincludes a seaming and cutting die configured to simultaneously compressthe web material along both sides of separation lines 120, and cut thematerial along separation lines 120. Heating energy may be supplied tothe seaming and cutting equipment such that the compression effectsthermal bonding of the web materials to form the seams 33 r, 33 l.

An advantage that may be provided by the foregoing manufacturing stepsis that they provide for the severing of the leg elastic members 38, 39such that they terminate neatly at locations proximate the longitudinaledges 21 of central chassis 20 (see FIG. 2), while their severed endsare held in place and prevented from retracting by being held in placewithin the laminate structure. This eliminates an unsightly continuationof these elastic members across the front and rear of the chassis, as ispresent in some currently marketed pant designs. Other currentlymarketed pant designs have severed leg elastics that terminate proximatelongitudinal edges of a chassis, but exhibit substantial “snap back,”wherein the severed ends of elastic members have retracted and/or curledabout within the structure, providing an unfinished, unsightlyappearance. The steps described above, in which the elastic members areadhered or otherwise secured between layers of a laminate structureprior to any severing, may help avoid this effect.

Hysteresis Test

Obtain samples of subject material sufficient to provide for a gaugelength of at least 15 mm along the direction of stretch in the Test, andshould be of a constant width (perpendicular to the direction of stretchin the Test) of at least 5 mm.

The Hysteresis Test can be used to various specified strain values. TheHysteresis Test utilizes a commercial tensile tester (e.g., from InstronEngineering Corp. (Canton, Mass.), SINTECH-MTS Systems Corporation (EdenPrairie, Minn.) or equivalent) interfaced with a computer. The computeris used to control the test speed and other test parameters and forcollecting, calculating, and reporting the data. The tests are performedunder laboratory conditions of 23° C.±2° C. and relative humidity of50%±2%. The samples are conditioned for 24 hours prior to testing.

Test Protocol

1. Select the appropriate grips and load cell. The grips must have flatsurfaces and must be wide enough to grasp the sample along its fullwidth. Also, the grips should provide adequate force to ensure that thesample does not slip during testing. The load cell is selected so thatthe tensile response from the sample tested is between 25% and 75% ofthe capacity of the load cell used.

2. Calibrate the tester according to the manufacturer's instructions.

3. Set the distance between the grips (gauge length) at 15 mm.

4. Place the sample in the flat surfaces of the grips such that theuniform width lies along a direction perpendicular to the gauge lengthdirection. Secure the sample in the upper grips, let the sample hangslack, then close the lower grips. Set the slack preload at 0.02 N/cm.This means that the data collection starts when the slack is removed (ata constant crosshead speed of 10 mm/min) with a force of 0.02 N/cm.Strain is calculated based on the adjusted gauge length (l_(ini)), whichis the length of the sample in between the grips of the tensile testerat a force of 0.02 N/cm. This adjusted gauge length is taken as theinitial sample length, and it corresponds to a strain of 0%. Percentstrain at any point in the test is defined as the change in lengthdivided by the adjusted gauge length times 100.

5(a) First cycle loading: Pull the sample to the specified strain(herein, 100%) at a constant cross head speed of 100 mm/min. Report thestretched sample length between the grips as I_(max).

5(b) First cycle unloading: Hold the sample at the specified strain for30 seconds and then return the crosshead to its starting position (0%strain or initial sample length, l_(ini)) at a constant cross head speedof 100 mm/min. Hold the sample in the unstrained state for 1 minute.

5(c) Second cycle loading: Pull the sample to the specified strain at aconstant cross head speed of 100 mm/min.

5(d) Second cycle unload: Next, return the crosshead to its startingposition (i.e. 0% strain at a constant cross head speed of 100 mm/min.

A computer data system records the force exerted on the sample duringthe test as a function of applied strain. From the resulting datagenerated, the following quantities are reported (note that loads arereported as force divided by the width of the sample and do not takeinto account the thickness of the sample):

i. Length of sample between the grips at a slack preload of 0.02 N/cm(l_(ini)) to the nearest 0.001 mm.

ii. Length of sample between the grips on first cycle at the specifiedstrain (l_(max)) to the nearest 0.001 mm.

iii. Length of sample between the grips at a second cycle load force of0.02 N/cm (l_(ext)) to the nearest 0.001 mm.

iv. % set, which is defined as (l_(ext)−l_(ini))/(l_(max)−l_(ini))*100%to the nearest 0.01%.

The testing is repeated for six separate samples and the average andstandard deviation reported.

The Hysteresis Test can be suitably modified depending on the expectedattributes and/or properties of the particular material sample to bemeasured. For example, the Test can be suitably modified where a sampleof the length and width specified above are not available from thesubject pant.

All patents and patent applications (including any patents which issuethereon) referred to herein are hereby incorporated by reference to theextent that it is consistent herewith.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.” All documents cited in the Detailed Description of theInvention are, in relevant part, incorporated herein by reference; thecitation of any document is not to be construed as an admission that itis prior art with respect to the present invention. To the extent thatany meaning or definition of a term in this document conflicts with anymeaning or definition of the same term in a document incorporated byreference, the meaning or definition assigned to that term in thisdocument shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is, therefore,intended that the scope of the invention is limited only by the appendedclaims and equivalents thereof.

What is claimed is:
 1. A disposable absorbent pant having a front waistregion, a rear waist region, and a crotch region, and comprising: acentral chassis occupying the crotch region and comprising left andright longitudinal edges; a liquid permeable topsheet; a backsheet, andan absorbent core disposed between the topsheet and the backsheet; abelt structure disposed about the central chassis, the belt structurecomprising an elasticized multilayer web overlaying a garment-facingsurface of the backsheet in the front and rear waist regions, the beltstructure extending laterally outward from the chassis and from each ofthe left and right longitudinal edges in each of the front and rearwaist regions, the belt structure having a front portion having a frontwaist edge, front left and right leg opening edges, and front left andright side edges, and the belt structure having a rear portion having arear waist edge, rear left and right leg opening edges, and rear leftand right side edges, the respective front and rear left side edges andthe respective front and rear right side edges being joined at sideseams, the belt structure forming a waist opening and left and right legopenings, wherein each of the front and rear portions of the beltstructure further comprises: an inner layer formed of an inner nonwovenweb; an outer layer formed of an outer nonwoven web; an intermediatelayer formed of an intermediate nonwoven web, and disposed between theinner layer and the outer layer; a waist elastic member disposed betweenthe inner layer and the outer layer, extending continuously in a lateraldirection across the portion, and having terminal ends proximate theside edges; and left and right leg elastic members each disposed betweenthe inner layer and the outer layer, each extending continuously along acurvilinear path along and proximate at least a portion of therespective left or right leg opening edge and each having a terminal endproximate the respective left or right longitudinal edge of the chassis,and proximate the respective left or right side edge; and a plurality ofshins in at least one of the inner layer, intermediate layer or outerlayer, lying about and oriented transversely to paths occupied by thewaist and leg elastic members; wherein at least one of the inner andouter layers is a wrapping layer that lies over a garment-facing surfaceof the central chassis, through the crotch region, wherein an addedelastic member is disposed on a garment-facing surface of the outerlayer, and wherein the added elastic member is disposed proximate one ofthe leg edges so as to be disposed nearer one of the leg edges than oneof the waist edges.
 2. The pant of claim 1 wherein the waist elasticmember of each of the front and rear portions of the belt structure isdisposed along and proximate the respective front or rear waist edge. 3.The pant of claim 1 wherein the waist elastic member and the left andright leg elastic members in each of the front and rear portions of thebelt structure are disposed between the inner layer and the intermediatelayer thereof.
 4. The pant of claim 1 wherein one of the waist elasticmember and left and right leg elastic members in each of the front andrear portions of the belt structure is disposed between the inner layerand the intermediate layer thereof, and another of the waist elasticmember and left and right leg elastic members in each of the front andrear portions of the belt structure is disposed between the intermediatelayer and the outer layer thereof.
 5. The pant of claim 1 wherein thewaist elastic member and the left and right leg elastic members in eachof the front and rear portions of the belt structure are disposedbetween the intermediate layer and the outer layer thereof.
 6. The pantof claim 1 wherein each of the front and rear portions of the beltstructure further comprises a third elastic member disposed between theinner layer and the outer layer and disposed between the waist elasticmember and the leg elastic members.
 7. The pant of claim 1 wherein theadded elastic member is disposed in an elasticized band structurebetween inner and outer band layers.
 8. The pant of claim 7 wherein theadded elastic member comprises a plurality of elastic strands disposedin the elasticized band structure between the inner and outer bandlayers.
 9. The pant of claim 1 wherein the waist elastic member and theleg elastic members in either or both the front portion and the rearportion of the belt structure differ from each other in a respectselected from the group consisting of number of elastic strands orbands, cross-sectional size of elastic strands or bands, cross-sectionalshape of elastic strands or bands, chemical composition of material fromwhich elastic strands or bands are formed, amount of pre-strain impartedduring manufacture, and combinations thereof.
 10. A disposable absorbentpant having a front waist region, a rear waist region, and a crotchregion, and comprising: a central chassis occupying the crotch regionand comprising left and right longitudinal edges; a liquid permeabletopsheet; a liquid impermeable backsheet, and an absorbent core disposedbetween the topsheet and the backsheet; a belt structure disposed aboutthe central chassis, the belt structure comprising an elasticizedmultilayer web overlaying a garment-facing surface of the backsheet inthe front and rear waist regions, the belt structure extending laterallyoutward from the chassis and from each of the left and rightlongitudinal edges in each of the front and rear waist regions, the beltstructure having a front portion having a front waist edge, front leftand right leg opening edges, and front left and right side edges, andthe belt structure having a rear portion having a rear waist edge, rearleft and right leg opening edges, and rear left and right side edges,the respective front and rear left side edges and the respective frontand rear right side edges being joined at side seams, the belt structureforming a waist opening and left and right leg openings, wherein each ofthe front and rear portions of the belt structure further comprises: aninner layer formed of an inner nonwoven web; an outer layer formed of anouter nonwoven web; an intermediate layer formed of an intermediatenonwoven web, and disposed between the inner layer and the outer layer;a waist elastic member disposed between the inner layer and the outerlayer, extending continuously in a lateral direction across the portion,and having terminal ends proximate the side edges; and left and rightleg elastic members each disposed between the inner layer and the outerlayer, each extending continuously along a curvilinear path along andproximate at least a portion of the respective left or right leg openingedge and each having a terminal end proximate the respective left orright longitudinal edge of the chassis, and proximate the respectiveleft or right side edge; and a plurality of shins in at least one of theinner layer, intermediate layer or outer layer, lying about and orientedtransversely to paths occupied by the waist and leg elastic members;wherein at least one of the inner, intermediate and outer layers is awrapping layer that lies over a garment-facing surface of the centralchassis through the crotch region, wherein an added elastic member isdisposed on a garment-facing surface of the outer layer, and wherein theadded elastic member is disposed proximate one of the leg edges so as tobe disposed nearer one of the leg edges than one of the waist edges.